Gas located within a fluid is compressible. Within a printing system, if a fluid ink contains one or more gasses, fluid ink to be ejected under pressure from an ink nozzle can therefore be compressed, due to the presence of gas, such that the ink may not jet correctly. Therefore, the presence of gas in a fluid ink that is intended for pressurized ejection reduces the reliability of producing an ejected droplet. In many such scenarios, the ink does not jet at all. Therefore, the presence of gas in a liquid ink can have a very large negative impact upon ink jetting, such as but not limited to the loss of printed material, which can be both costly and frustrating.
Vacuum degasification has previously been used in some printing systems. FIG. 1 is a schematic view of an exemplary conventional exemplary printing system 10 having inline vacuum degasification. Ink 14a, such as stored within an ink supply reservoir 12, e.g. a cartridge or tank, is transported 16 through a vacuum degasification module 18. A vacuum source 20, e.g. a pump or venturi, is also typically connected 22 to the vacuum degasification module 18, which applies a vacuum to the ink 14a within the vacuum degasification module 18, thereby extracting one or more gasses from the incoming ink 14a, producing degassed ink 14b, which is delivered 24 to a print head 26, wherein the print head 26 is configured to controllably jet 28 the degassed ink 14b onto a substrate 30.
Some conventional vacuum degassing modules are available through DIC Corporation, of Tokyo, Japan, wherein different modules are specified based on the type of ink to be jetted, the capacity, and the desired level of degassing. Other degassing devices are available through Membrana Inc., of Charlotte, N.C. A wide range of filter capsules is also available through Pall Corporation, of Port Washington, N.Y.
While vacuum degasification has previously been used to remove some gases from ink, such systems are often complex, and typically require a pressure source or a vacuum source.
It would therefore be advantageous to provide a mechanism that is configured to remove gasses that may be present in an ink at any point within a printing system, without requiring vacuum degasification and related hardware. The development of such a system or structure would be a major technological breakthrough.
Sonication has been used previously in applications other than printing, to break down larger particles into smaller particles. For example, ultrasonic energy has previously been used to break down kidney stones in a medical environment.
Besides problems with resident gasses, particulates in an ink supply have also posed numerous problems. For example, nozzle clogging due to particulates is a common print head failure mode in printing systems. Particulates, such as but not limited to agglomerated particles, are often present within an ink, or may occur within an ink delivery system, in a printing environment. While relatively small particles may pass though an ink delivery system, and be jetted through an inkjet print head along with the liquid ink, larger particles can easily build up within ink delivery circuits, and often clog print heads and associated pathways, e.g. within one or more nozzle plates.
It would therefore be advantageous to provide a mechanism and associated process that is capable of breaking down the size of particulates that may be present in an ink, at any point within a printing system, to prevent fouling. The development of such a system, structure, and associated process would provide a major technological advance.
In addition, while prior vacuum degasification systems may be configured to remove resident gases from an ink supply, such systems do not address other solids that may be present in the ink, such as agglomerated pigments.
It would therefore be advantageous to provide a system, structure, and associated process that is capable of both removing resident gases from an ink supply, and maintaining the size of particulates in the ink supply, at any point within a printing system. The development of such a system, structure, and associated process would constitute a further major technological breakthrough.